Chair base device

ABSTRACT

A supporting structure for tiltably mounting a chair seat or the like in which a frame secured to the seat bottom has a vertically disposed shaft means thereon of which the opposite end is secured to a half spherical ball. The half spherical ball is inserted into a block having an upwardly open cavity of which the bottom of the said cavity is of semi-spherical configuration thereby providing means for a chair seat or the like for tilting or rocking motion, or a combination thereof. Spring means are utilized for biasing this structure to a predetermined position. Restriction means are selectively engageable for prevention of a swivel or tiltable movement of the assembly.

nited States Patent 1191 Somerset, Mass. 01609 [22] Filed: Mar. 11, 1971 [21] Appl. No.: 123,285

[52] US. Cl 248/372, 248/398, 272/54 [51] Int. Cl. Fl6m 13/00 [58] Field Of Search 248/160, 371, 372, 398;

[56] References Cited UNITED STATES PATENTS 368,652 8/1887 Class 272/54 X 619,596 2/1899 Mayer 248/398 849,975 4/1907 Carlson 248/372 1,070,278 8/1913 McKinney 248/379 1,890,696 12/1932 Rosehahn 248/160 X 2,679,369 5/1954 Palley 248/5 3,078,092 2/1963 Mills 272/55 Ollerheadfl Jul 9, 1974 CHAIR BASE DEVICE 3,103,356 9/1963 Heines 272/52 [76] Inventor: Rolfe Ouerhead, 188 Centre St" 3,220,726 11/1965 1401161 et a1. 272/52 3,544,159 12/1970 Andersson ..248/373' Primary Examiner-William H. Schultz [57] v 1 ABSTRACT A supporting structure for tiltably mounting a chair seat or the like in which a frame secured to the seat bottom has a vertically disposed shaft means thereon of which the opposite end is secured to a half spherical ball. The half spherical ball is inserted into a block having an upwardly open cavity of which the bottom of the said cavity is of semi-spherical configuration thereby providing means for a chair seat or the like for tilting or rocking motion, or a combination thereof. Spring means are utilized for biasing this structure to a predetermined position. Restriction means are selectively engageable for prevention of a swivel or tiltable movement of the assembly.

' 10 Claims, 2 Drawing Figures CHAIR BASE DEVICE This invention relates to tiltable chairs or the like and more particularly to a structure utilizing a half spherical ball and a block whose upwardly open cavity is of semi-spherical configuration for supporting a chair seat for a tilting or rocking motion.

The prior'art forms of supporting structures have had various disadvantages in that they have included many intricate parts of expensive manufacture, such parts have been large, cumbersome, and relatively heavy, thereby adding undesirably excessive weight to the chair construction; and/or they have been of unsightly construction detracting from what might have been an otherwise aesthetic appearance to the chair.

It is an object of this invention to provide a supporting structure for a tiltable chair seat or the like which structure is few in number of parts, well suitable to mass production techniques, relatively lightweight and compact construction, and will not impart an undesirable appearance to the chair or the like.

It is a further objective of this invention to provide an improved supporting structure for a tiltable chair seat or the likewith restriction means which are selectively engageable for prevention of a swivel or tiltable movement of the assembly.

It is a more specific object to provide a chair seat or the like supporting structure including a frame adapted for securement to the bottom of the chair seat and having a vertically disposed shaft of which the opposite end is secured to a half spherical ball. The half spherical ball is inserted into a block having an upwardly open cavity of which the bottom of said cavity is of semispherical configuration.

Some of the objects of the invention having been stated, other objects will appear as the description proceeds when taken in connection with the accompanying drawing, in which! FIG. 1 illustrates one embodiment of chair seat and a supporting structure for tiltably mounting a chair seat or the like according to this invention;

FIG. 2 is a sectional view exposing the central portion of the supporting structure thereby showing the means that permit the chair seat or the like for tilting or rocking motion, or a combination thereof.

Referring more specifically to the drawing, a tiltable swivel chair comprising a chair seat 32 and a supporting structure is shown in FIG. 1 provided with one embodiment of the chair seat or the like supporting structure of this invention. The supporting structure 10 may be of conventional or other construction and, as is shown, the supporting structure 110 includes an up standing central body or block having an upwardly open cavity 30 therein. A plurality of outwardly extending supporting legs 24, 25, 26, 27 are attached to the supporting structure 10.

The chair seat or the like supporting structure 10 comprises a platform 3 which preferably is in the form of a relatively thin strong material adapted to be secured in a horizontal position to the bottom of the chair seat 32, as illustrated in FIG. 1. A vertically disposed shaft 11 is secured to and depending from the platform 3 by a rod 4 and a semi-spherical member 12 on the lower end of the shaft 11. This semi-spherical member 12 is complementary to and engaged with the semispherical bottom of the cavity 30 whereby it is universably movable with respect to the supporting structure 10.

The supporting structure 10 has selectively engageable means for restricting movement of the assembly as shown in FIG. 2 which comprises a laterally slidable fork 19, 20 which straddles the shaft 11 and bears against the upper surface of the semi-spherical member 12 when in the engaged position. This laterally slidable fork 19, 20 is engaged to restrict the tiltable movement of the chair seat or the like with respect to the support ing structure 10. Further restricting movement of the assembly is provided wherein a selectively engageable means comprises a laterally slidable rod 29 which passes through an aperture 21 in the shaft 11 when in an engaged position. This laterally slidable rod 29 isengaged to restrict the swivel movement of the chair seator the like with respect to the supporting structure 10.

The supporting structure 10 further comprises a flexible boot 28 as shown in FIG. v2 fixedly secured to the shaft 11 and to the upstanding central body at a point of a cover 9 that is removable to perform maintenance upon the assembly located within the cavity 30.

The supporting structure 10, as illustrated in FIG. 2, further comprises spring means 13, 14, l5, 16 for biasing the assembly to a predetermined position whereas a plurality of spring means 13, 14, 15, 16 are joined at one end to the outer walls of the cavity 30 and at the other end to a collar 36 loosely surrounding the shaft 11.

The supporting structure 10 may be employed as a base for items other than achair seat 32 therefore engagement'of a teeter-totter 31 is shown in FIG. 1 by securement to the supporting structure 10 with nuts 33 and bolts 34, 35 through holes 5, 6, 7, 8.

It is thus seen that I have provided a supporting structure for mounting a tiltable chair or the like, wherein a vertically disposed shaft means is secured-to a platform for the chair seat or the like of which the opposite end is secured to a half spherical ball. The half spheri cal ball is inserted into a block with an upwardly open cavity of which the bottom of the said cavity is of semi spherical configuration thus providing a simple, compact, easily assembled and economical assembly.

In the drawing and specification there have been set forth preferred embodiments of the invention 'and although specific terms are employed, they are utilized in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being defined in the claims.

Having thus described the invention, there is claimed as new and useful, and is desired to be secured by let ters patent:

l. A supporting structure for tiltably mounting a chair seat or the like comprising a block, said block having an upwardly open cavity, the bottom of said cavitybeing of semi-spherical configuration, a platform adapted for attachment to a chair seat or the like, an assembly comprising a vertically disposed shaft secured to and depending from said platform and a semispherical member on the lower end of said shaft, said semi-spherical member being complementary to and engaged with the semi-spherical bottom of said cavity whereby said assembly is universably movable with respect to said block and means selectively engageable with said assembly for restricting movement of said assembly to swivel motion.

2. A supporting assembly according to claim 1 wherein the selectively engageable means for restricting movement of the assembly comprises a laterally slidable fork which straddles the shaft and bears against the upper surface of the semi-spherical member when in engaged position.

3. A supporting structure according to claim 1 comprising a flexible boot fixedly secured to the shaft and to the block.

4. A supporting structure according to claim 1 comprising a plurality of outwardly extending supporting legs attached to said block.

5. A supporting structure according to claim 1 comprising spring means for biasing said assembly to a predetermined position.

6. A supporting structure according to claim 5 wherein the spring means comprises a plurality of springs each joined at one end to the block and at the other end to a collar loosely surrounding the shaft.

7. A supporting structure for tiltable mounting a chair seat or the like comprising a block, said block having an upwardly open cavity, the bottomof said cavity being of semi-spherical configuration, a platform adapted for attachment to a chair seat or the like, an

assembly comprising a vertically disposed shaft secured to and depending from said platform and a semispherical member on the lower end of said shaft, said semi-spherical member being complementary to and engaged with the semi-spherical bottom of said cavity whereby said assembly is universably movable with respect to said block and means selectively engageable with said assembly for restricting movement of said assembly to a single vertical plane.

8. A supporting structure according to claim 7 wherein the selectively engageable means comprises a laterally slidable rod which passes through an aperture in the shaft when in engaged position.

9. A supporting structure according to claim 7 comprising means selectively engageable with said assembly for restricting movement of said assembly to swivel motion.

10. A supporting structure according to claim 7 comprising a flexible boot fixedly secured to the shaft and to the block. 

1. A supporting structure for tiltably mounting a chair seat or the like comprising a block, said block having an upwardly open cavity, the bottom of said cavity being of semi-spherical configuration, a platform adapted for attachment to a chair seat or the like, an assembly comprising a vertically disposed shaft secured to and depending from said platform and a semi-spherical member on the lower end of said shaft, said semi-spherical member being complementary to and engaged with the semi-spherical bottom of said cavity whereby said assembly is universably movable with respect to said block and means selectively engageable with said assembly for restricting movement of said assembly to swiVel motion.
 2. A supporting assembly according to claim 1 wherein the selectively engageable means for restricting movement of the assembly comprises a laterally slidable fork which straddles the shaft and bears against the upper surface of the semi-spherical member when in engaged position.
 3. A supporting structure according to claim 1 comprising a flexible boot fixedly secured to the shaft and to the block.
 4. A supporting structure according to claim 1 comprising a plurality of outwardly extending supporting legs attached to said block.
 5. A supporting structure according to claim 1 comprising spring means for biasing said assembly to a predetermined position.
 6. A supporting structure according to claim 5 wherein the spring means comprises a plurality of springs each joined at one end to the block and at the other end to a collar loosely surrounding the shaft.
 7. A supporting structure for tiltable mounting a chair seat or the like comprising a block, said block having an upwardly open cavity, the bottom of said cavity being of semi-spherical configuration, a platform adapted for attachment to a chair seat or the like, an assembly comprising a vertically disposed shaft secured to and depending from said platform and a semi-spherical member on the lower end of said shaft, said semi-spherical member being complementary to and engaged with the semi-spherical bottom of said cavity whereby said assembly is universably movable with respect to said block and means selectively engageable with said assembly for restricting movement of said assembly to a single vertical plane.
 8. A supporting structure according to claim 7 wherein the selectively engageable means comprises a laterally slidable rod which passes through an aperture in the shaft when in engaged position.
 9. A supporting structure according to claim 7 comprising means selectively engageable with said assembly for restricting movement of said assembly to swivel motion.
 10. A supporting structure according to claim 7 comprising a flexible boot fixedly secured to the shaft and to the block. 